FAYETTEVILLE (AP) - Bobby Petrino isn't about to let go of Arkansas' hopes or expectations for the season following Knile Davis' ankle injury.

Instead, the Razorbacks coach has every intention of using the loss of the Southeastern Conference's leading rusher as motivation.

Davis injured his left ankle early during the scrimmage portion of practice Thursday evening. Petrino said the junior, who led all SEC running backs with 1,322 yards rushing last season, had surgery that evening and is expected to miss the season.

Davis' loss leaves an obvious void in production on the field for Arkansas, which is still looking for Ryan Mallett's successor at quarterback. It also opens the possibility of a hangover of sorts for the Razorbacks, who watched the team's emotional leader carted off the field following the injury.

Petrino is confident Arkansas will find the offense, and he's counting on experience to help stabilize the Razorbacks' psyche.

"We've got two ways we can handle it," Petrino said. "No. 1, we can use it as an excuse. It's an excuse all year long, or we can use it as the No. 1 motivating factor to work as hard as we can to be a good football team.

"So we'll see how we handle it."

Junior running backs Dennis Johnson and Ronnie Wingo are likely to step in for Davis in the short term. The trio shared carries early last season before Johnson suffered a season-ending injury of his own and Davis took the reins of the Razorbacks offense.

Johnson has averaged 6 yards per carry on 102 rushing attempts in his career, including 9.2 yards per carry last season on nine attempts before his injury. Wingo has 572 yards rushing on in two seasons at Arkansas, and he had 27 catches for 274 yards last season.

Also, Petrino has praised the work of freshman running back Kody Walker during fall practice. Fellow freshman Kelvin Fisher was moved from cornerback to running back following Davis' injury.

"The one thing I know about this team is we've been able to overcome situations like that before," Petrino said. "Other guys jump in and step up and come together closer as a team, and that's what we need to do."

Davis' absence leaves Petrino without his offensive security blanket from last season, the running back he turned to when closing out games as Arkansas went 10-3 and reached its first BCS bowl game in the Sugar Bowl. Adding to that loss is the fact the Razorbacks are replacing three starters on the offensive line this season - as well as Mallett, the record-setting quarterback now with the New England Patriots.

Junior Tyler Wilson has been thought to be the frontrunner in the quarterback competition with sophomore Brandon Mitchell since the spring, and he performed well following Davis' injury during the scrimmage. Whoever wins the job will have the benefit of relying on a quartet of receivers - Joe Adams, Greg Childs, Cobi Hamilton and Jarius Wright - all selected to the preseason Biletnikoff Award watch list.

Petrino said Davis' loss won't have a dramatic impact on Arkansas' playbook at the moment, if for nothing else because the coach hasn't settled on this team's best offensive plays yet.

"It's not like we're changing, because we're in the process of finding what our identity is right now," Petrino said. "We just have to continue to work and see how we're gonna be most effective operating the offense.